Abrasive and polishing tape



May 25, 1948- M. G. WALLICH ABRASIVE AND POLISHING TAPE Filed Sept. '25, 1946 lNl/ENTOR MflUR/CE GLWAZZ/CH A TTOAWEY- Patented May 25, 1945 ABRASIVEAN D POLISHING TAPE Maurice G. L. Wallich, Vancouver, British Columbia, Canada, assignor, by mesne assignments, to Paper Strap, Inc., .Portland, reg., a corporationof Oregon:

Application September 25, 1946, Serial No. 699,325

2 Claims. 1- Thepresent invention relates to a new and'improved abrasive and polishing tape.

The abrasive or'polishing strips now available usually comprise asingle layer of paper, cloth or the-Iikewith-the abrasive or polishing grains secured to one or'both sides by means of a suitable binder. Paper is preferred as a backing sheet because of its lower cost. While the abrasive coated paper strips are satisfactory for most sanding or polishing applications they are not particularly useful-for thefi'nishing of rounded surfaces, particularly spherical or other surfaces of compound curvature, primarily because paper does not possess sufficient give or stretch for the normally flat strips to conform to such rounded surfaces.

It is an object of the present invention to provide a new and improved abrasive coated'paper in tape or roll form'which is inexpensiveand strong and is particularly useful for sanding, polishing or buffing rounded surfaces.

A further object of the invention is to provide a new and improved sandpaper comprising a backing member in the form of a folded paper tapeso constructed as to cushion the sanded surface and to assure a firm, even contact of the abrasive coated side of the tape with rounded or irregularly curvedzsurfaces.

In accordance with the present invention there is provided an abrasive or polishing tape comprising a backing member obtained by folding the opposite marginal edge portions of a strip of relatively thin-and tough paper over upon itself a plurality of: times. I he folded edge portions extend on the same side'of the strip, the width of each folded portion being slightly less than one-half the total width of the finished tape whereby the folded port-ions'lieflat in anonoverlapping relation against the central strip portion. The folded tape is provided with a multiplicity of closely adjacent creases or crimps extending through all of the layers thereof whereby the folds are set and the tape rendered relatively flexible or pliable. The folded side of the tape is then provided with a layer of abrasive of polishing material adhesively secured thereto by means of any of the numerous adhesives employed in the manufacture of sandpaper and the like. The resultant product comprises two parallel abrasive coated surface portions joined at their outer edges by means of the central strip portion forming the principal backing portion of the tape and a plurality of cushioning layers of paper sandwiched between the abrasive coated portions and the central strip portion.

Additional objects and advantages of the invention will become apparent from the following description thereof and by reference to the accompanying drawing.

In the drawing; Figs. 1 and 2 are perspective views illustrating the opposite sides of an abrasive tape constructed in accordance with one form of the present invention; Fig. 3 is a perspective view illustrating a further modification of the invention; Fig. 4 is a fragmentary view partly in section illustrating a typical application of the abrasive tape ofthe invention, and Fig. 5is an enlarged cross sectional view taken along line 55 of Fig. 4.

Referring to Figs. 1 and 2,'there is shown a section of abrasive tape as comprising an elongated strip of relatively thin tough paper, such as kraft paper, and whichhas each of its opposite marginal edge portions folded over upon itself a plurality of times throughout its entire length. These folded portions H and I2 are arranged on the same side ofthe tape for reasons as will subsequently appear. In order to provide the desired tensile strength for the tape, the opposite edge portions are folded" over preferably not-less than three times, inwhich case four thicknesses of paper occur at each edge. I t will be noted that the-raw edge of thestrip of paper from which the tape is formed is thus arranged'within each folded portion of the product so that only folded or doubled edges of paper extend along the edges of the twofolded portions ll andlZ of the prodnot to providemaximum strength and toughness thereto for resisting any tendency for the tape to be torn through. It will benoted also that the folded edge portions H and I2 are each about one-half" the width of the finished tape in order th'atthe two folded edge portions will lie flat, that is, in a substantiallytouching but nonoverlapping relation against the backing portion is of the paper strip extending therebetween.

In the modification illustrated in Fig. 3, the opposite edge portions I! and I2 are folded upon themselves a plurality of times but in a somewhat different manner than in the previously described form. However, in both modifications only folded or doubled back edges of paper extend along the flat outer faces 16 and H of the folded edge portions l l and [2.

Since the opposite edge portions H and i2 are folded over a plurality of times, the tape will initially be inherently relatively stilf and. the edge portions will have a natural tendency to unfold. In order to render the tape relatively flexible and pliable and also to set the folds, a continuous succession of adjacent creases are formed transversely and throughout the full length thereof, each of the creases being furthermore formed in all of the superimposed layers of paper of each of the folded edge portions. This can be accomplished by drawing the tape through a plu-,

rality of relatively sharp bends in opposite directions such as over a number of suitably arranged, relatively small diameter rods or rollers whereby,

due to the difference in radius of curvature be tween the inner and outer layers of thefolded tape, buckling occurs with the resultant formation of a multiplicity of creases on both front and back sides of the tape and as a, result the tapeis rendered relatively pliable and the folds are compresed and firmly set. The creases thus formed are indicated in Figs. 1 and 2 at M.

tact with the work piece. As a result, spotty or 22,.the rung being rotated about its longitudinal axis during the finishing thereof with the abrasive tape held at right angles to that axis buckling of the layers of paper forming or adjacent to the faces l5 and il plus the cushioning As an added result of the creasing of the vari- 7 ous layers, the cushioning effect of the intermediate layers of paper in the folded portions l l and I2 is also increased.

' The coating of'abrasive or polishing material can be applied to the outer surfaces 16 and I! of the folded portions II and I2 respectively either before or after the creasing'operation. Any of the usual binders can be employed for securing theiabrasive or polishing material, examples of such binders being the various cellulose derivatives, such as ethyl cellulose, cellulose esters, etc., phenolic resins, alkylresins, glue or suitable mixtllres of one or more of these adhesive materials with or without modifiers, plasticizers, etc. Like- 'Wise;the invention is notlimited to any particular abrasive material, sand, alumina, emery dust, and carborundum being mentioned merely as representative of the class of abrasive and polishing materials which canbe employed, the selection of a specific materialdepending on the intended use'of the tape.

: "Thefinished abrasiveor polishing tape is par- 'ticularly suited for-the finishing of rounded surfaces first because of the fact that it wi-ll'fold longitudinally along a line between the two folded edge :portions 1 l and 12 so that more uniform contact of the tape with a curved or spherical surface of a work piece is possible, and secondly, be- "cause of thefact that when the abrasive coated 'side'ofthe' tape is brought'into contact with a rounded surface; the central backing portion l3 takes up most of the strain resulting from hold- When thus used,the tape folds along its center ,line tobring faces l6 and E! into engagement with the rounded surface while the crinkling or the specific details shown and described herein are merely illustrative and that'this invention may be carried out by other means.

What I claim is: g, 1. A flexible abrasive coated tape comprising a fiat strip of relatively thin tough paper, each of the opposite edge portions of said strip being folded over upon itself a plurality of times, the folded edge portions extending in nonoverlapping relation and substantially meeting along the center line on the same side of said strip, and a layer of abrasive material adhesively secured to the surfaces of said folded edge portions.

2. A flexible abrasive coated tape comprising a flat strip of relatively thin tough paper, each of the opposite edge portions being folded over upon itself, the folded edge portions meeting substantially along the center line on the same side of said strip and a layer of abrasiveparticles bonded to the outer surfaces of said folded edge portions. MAURICE G. L. WALLICH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Great Britain 1859 

